


Sans is In-fer-Red

by ThatThing



Category: Undertale (Video Game)
Genre: Bar, Bara Sans (Undertale), Choking, Domination, Dubious Consent, Knotting, M/M, Marking, Mild Cum Inflation, Monster Heat, Rape/Non-con Elements, Rough Sex, Scratching, Smut, Underfell Sans (Undertale), degrading, dom Classic, dub-con, no beta we die like men, normal sized Red, spitting, sub Red
Language: English
Status: Completed
Published: 2020-09-25
Updated: 2020-09-25
Packaged: 2021-03-07 19:14:14
Rating: Explicit
Warnings: Rape/Non-Con
Chapters: 1
Words: 3,082
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26642785
Author URL: https://archiveofourown.org/users/ThatThing/pseuds/ThatThing
Summary: Papyrus suggested that Sans should go out and make friends. This is probably not what he meant.Sans decides to go out to a bar and lo and behold, there is one of his alternates. A very sweet smelling Underfell Sans, maybe he'd be willing to have a good time tonight?
Relationships: Kustard, Sans/Sans (Undertale)
Comments: 8
Kudos: 51





	Sans is In-fer-Red

Papyrus called and said to get out, make friends and do something, anything since they've gotten on the surface on repeat. It's just, what's the point? He knows resets aren't going to happen but after so long of not caring or doing anything because it was going to get ripped away again, it's hard to get up and do things again. So now, here he is, at a random bar so his brother couldn't track him down and a barely touched beer in hand. Leaning up against the wall of the establishment, Sans is thinking about heading back when a smell hits him. It's so unbearably sweet, making his head feel light and just the most crazy idea pop into his head. Papyrus did say to try and make friends didn't he?

Pushing himself off the wall, Sans picks his way across the dimly lit bar. Slipping past people, monsters, and tables, he heads towards the front with care due to his large size. The sweet smelling monster's scent grew stronger the closer he got to the entrance. This monster had to be in some kind of heat with how it's making his bones buzz. Worry started to grow that he wouldn't be able to find the monster until he saw them and it made his legs feel like jello. 

There, moving uncomfortably towards the nearest bar stool was a petite skeleton a good 3 feet shorter than himself. From the looks of it, as they glanced around and made the briefest eye contact with him, a fellverse skeleton. Those ones started recently popping up not long ago causing havock to all the progress they made with humans with how aggressive they acted. 

Seeing the pointed teeth, red eye light and equally red blush on their face, he knew this was not only a fell monster, but one that's in heat. His idea gets even more crazy. 

As this fellverse skeleton took their place at the bar side, Sans saunters on up trying to make a cool and relaxed face despite the scent radiating off the other skeleton. Inserting himself between the skeleton and a human, who while looking uncomfortable, eventually slid off their stool for another seat. The fell skeleton instantly, stiffened up and shot a glaring look up at Sans who only waves in return making the smaller shrink back slightly.

"The fuck do you want? Tryin'a pick a fight with me ya over grown ape?" The fell skeleton snaps making Sans smile.

"No not at all. I'm just here to say hi, never seen you around here before and-"

"Well you can back your fuckin' ass off cus I'm not interested in makin' any friends!"

Frowning slightly at that, the fell monster's mouth twitches up in a small triumphant grin. "I'm sorry to hear that," is all Sans says before slowly backing off. Moving away from the new skeleton, Sans figures he'll just have to bide his time then. It'd be easier taking the smaller if they're drunk after all, it'll make less of a scene than they've already caused tonight.

~~~

Watching the large fucker tromp away, Red drags his eyes away to look back to the bar. He really needs something strong tonight. All day he's been getting weird looks from his brother and overall feeling like shit. Warm then cold the moment he touches something, those touches just making his bones feel like electricity is running through them then this giant bugging him? If he didn't know any better, he'd say he's in heat but that's impossible! Fell monsters don't get heat. Not in the hell they live in. Children there are a liability and so were heats so out went with both unless you were insane or unlucky.

Ordering anything they had with high alcohol content, Red only planned on getting smashed as soon as possible and leaving to ride it out at home. Right now he just wants to throw coherent thought out the door and forget about today and how clingy he feels right now. Him in heat? Nah.

~~~

It takes about an hour before the skeleton he's been spying on gets cut off and after some argument with the bartender, eventually slides off and puddles to the ground with an angry huff. Taking this as his chance, Sans comes up to the bar side and carefully picks the smaller skeleton up from off the ground and puts their drunken body into his arms. Almost immediately the red tinted skeleton starts yowling like a cat and fighting in his arms screaming for him to let go. 

"LET ME GO YA FUCKIN' ASSHOLE! I DON'T KNOW WHAT YOU'RE TRYIN' TO DO BUT I'M GONNA KICK YOUR ASS AND KILL YOU, YOU APE LOOKING MOTHER FUCKER!"

Trying to keep his face even, Sans gives the bartender an apologetic look. "Sorry buddy, just gonna take my friend home and get him out of your hairs. He's not thinking right right now," he explains smiling sheepishly which earns him a suspicious look but otherwise garners no protest. Sans' smile spreading widely on his face, he turns to take his prize home, exiting the building and going down the road. With all this moving and rubbing, he can already tell that the flush of their face is more than just the booze they'd been guzzling for a better part of two hours.

"You sure know how to make a guy wait," he carefully puts a hand on the smaller's neck and squeezes tightly making them gag in surprise, "you little whore teasing me all night with your scent. Should've just taken the offer when you had the chance," Sans growls as he takes a turn into a dead end alleyway. By then, the small skeleton's body has gone limp in his arms and he releases his grip on their neck. Running a finger along the very obvious red mark already growing on their neck he snorts smugly and teleports to his home.

Landing in the living room on his one bedroom ratty looking apartment, he takes his goods swiftly into the bedroom. Gotta prepare them before they wake up and can do anything to try and get out. Pushing the door to his room open he lays his prize in the middle of his unmade bed. Admiring the little monster, Sans couldn't help but lean in and get another whiff of the sweet scent. Moving in closer than that, he's nuzzling into the crook of the skeleton's neck and purrs softly. Such an amazing scent even coming from his look alike. 

Pulling back begrudgingly, Sans finally takes the time to undress the skeleton before him. Jacket, pants, shirt, he stops at what he finds under the shirt. Scars, so many scars littering across their body and the telltale slash the kid makes across his chest on this skeleton's body to. Snarling, the thought definitely throws him out of the mood but nothing that this monster's sweet heat scent won't fix in a few minutes. Picking at some of the scars with his fingers, he can definitely tell some of them aren't from battle which definitely pisses him off. Then he sees it, a collar.

His eyes widening at the sight of it, he runs a finger under it feeling the magic of some other strange monster's magic running through it. It's almost like he just caught someone else's lost little puppy. This definitely gives him some ideas to do with his new pet but the collar they have on now will have to do. Giving the leather a few tugs, he releases it and goes about undressing the rest of his new pet's clothes. With that done, he goes through the pockets of the skeleton's clothes until he finds a wallet and a cell phone. Tossing the clothes to the side, he shuts off the cell phone and tosses it to the other side of the room.

Opening the wallet, Sans quickly finds what he looking for, an ID. Generally what the monsters in fellverse did to differentiate themselves from their counter parts was either change their whole name, part of their name, or added to it. This guy gave himself a whole new name, more than likely against his Papyrus' insistence. The little guy's name is Red, how cute.

Tossing the wallet with the rest of the smaller's clothes, Sans figures he should probably start moving. The guy will be waking anytime soon now. He did only choke him out after all. He doesn't want anything too restrictive, there'd be no fun in that. Moving to one of the drawers against the wall, he opens it and pulls out a long lead of twine. Taking it out, he takes it back to Red and securely ties it to their collar. Giving it a little tug to make sure it stays, it manages to do that and rouse his prize from their slumber.

Red blinks around blearily, visibly confused to what's going on until their eyes landed on Sans. Their eyes widen, and their nose flares up in alarm making Sans laugh as they jolt up and try to bolt off and away from him only to be tugged to the floor with the twine and an "oomf."

Rubbing at their head, Red is hardly given a chance to recover before the twine is tugged harshly once more making the smaller gag as they're raised high enough for Sans to grab and hoist them back onto the bed. Placing them back to the bed, he's quick to press a heavy hand into the smaller's sternum forcing the breath out of their non-existent lungs.

Sans wants to admit it, but the way this copy was looking up at him. Their eyes had such a defiant front but it was just so easy to see the fear settling in the depths of those eyes. 

"Now don't you regret that?" Sans asks, only getting a choked wheeze in response with his continued pressure. Slowly releasing pressure, Red is quick to start sucking air as his throat starts to open up. Once the pressure was almost completely released, Sans stops. Moving to loom over the other. He holds the twine all together just above Red's head under one tight fist.

Licking his teeth slowly, Sans looks the smaller monster dead in the eyes and says slowly, "as much as I'd loved to tease you more. I think it's about time that I get this moving..." 

"Fu- fuck you," Red manages to croak out and tries to spit up into Sans' face only for the red glob to not even have any air and come up thickly from their mouth. Slowly, the spit slides down the side of their face, eyes widening as an almost vengeful look spreads across Sans' face.

Chuckling softly, Sans takes a finger and dipped it into the spit, running his finger down their face and their neck. Pupils small, Red waits, his eye lights shacking softly with anticipation until the larger monster finally speaks.

"Are you that fucking stupid? Not only do you spit on yourself but you don't know any other phrase aside from, "fuck you," I thought you were better than that but I guess not. Good thing I picked up your whoring ass for sex and not your brains!" Sans snaps. Instantly, as a protest obviously started to bubble from Red's mouth, as soon as their sharp jaw opened, Sans shoves his already spit coated fingers into Red's mouth stopping the words he was about to say.

Hooking his fingers around Red's jaw, Sans pulls down on it so hard that he could feel the joint creaking in protest from it or just Red whining about it. "Now, I want you to shut up or else I'll tear those little shark teeth out of your skull. Got it?" He explains impatiently then slowly pulling his fingers out to let cold strands of spit follow out briefly before breaking and landing coolly on Red's chin.

Getting a hard swallow and a nod from the smaller monster below himself Sans gets the twine and carefully takes Red's wrists and binding them tightly above the fell monster's head. The bindings were so tight that Red releases a hard breath as his fingers quickly started to turn numb.

Eyeing Red's pelvis, Sans starts to ghost his fingers around the bone slowly feeling out where would get the little guy going the most. It didn't take long. One good rub on the coccyx earns Sans a low whine and desperate shifting from the little shit.

In long languid rubs he pulls soft moans from Red, feeling their magic heat up as his own did as well with renewed excitement. Spotting his mate eyeing his package, Sans chuckles softly, "don't worry. You'll be feeling it real soon." With this slight distraction, Sans digs his nail into the tail bone making Red screech and finally break his silence.

"FUCK!" Red yowls as sweat beads down his skull as unformed magic congeals inside of their pelvic girdle and more solid magic blooming across their heated body.

"Huh," that works, Sans thinks as he pulls his hand back only to pump his hand back inside making Red spasm underneath him and choke out, "stop!"

It's so cute that this monster thinks he still has a choice. But he'll give it to them. "On one condition, you have to form a nice cunt for me to fuck. If not," pulling his hand back once more Sans pumps his fist once more inside of Red but this time, he kept going.

"Guk, ah AH," Red moans and tries desperately to pull his bound hands down from Sans' grasp but of course fails. The bara monster could feel the magic itself start to heat up and slowly become harder to move as it tries to form but is held back. Wouldn't want it to tear after all. "F FINE, TAKE IT OUT PLEASE!" Red begs with a burst of noise and few weak kicks of his legs. 

"Good puppy," Sans coos and pulls his thickly covered slimed hand out slowly. The moment his hand fully left, Red went through and made him a nice little pussy for him to fuck. 

Not giving the smaller much of a chance, he inserts two of his slick fingers inside of Red feeling the magic stretch over his bones making the smaller softly whimper as drool starts to drip down their face from how much their mouth has been open.

It doesn't take much before Red's vag starts to stretch and is able to accommodate more and more fingers. Already slickening with more of it's own goo. Not able to take it much longer Sans moves his hand away from pinning Red's arms up to pawing at his own bulge trapped tightly inside his pants. Huffing softly, he rubs himself in sync to his fingers pace.

Groaning lowly, Sans takes a peak at how Red is doing. Not much left in the little guy from the looks of how much drool is dried on their mouth and how hazy their heated eye lights are. Good.

With great haste, Sans moves his hands to his waist and swiftly shimmies down his pants to his knees, freeing his cock to the air allowing it to stand stiffly in the air. Grabbing ahold of Red's hips, he raises them slightly to align then lay flush to his dick, already his knot starting to peak . The lips quiver against his manhood and Red whimpers eye lights becoming more clear for a moment then flashing with color as Sans slides his dick inside quickly.

"Fuckin', by the angel," Red moan/screams out, flaring his arms up to hook their neck but that only made them slightly hang themselves. Sans can hear the soft wheezes of breath below himself but chooses to ignore it. 

Digging his nails into the smaller's hips, he thrusts faster and faster. Continuing to ignore the pained noises coming from his mate as he tears up the inside of their vagina. His knot rapidly popping in and out of his heated mate, arousal mixing with bleeding magic as the tears grow. 

Red manges to hook his fingers around Sans' back ribs, digging his own, much sharper claws into Sans' back making the monster grunt and even groan slightly as Red releases his grip and claws his nails up Sans' back. Blue magic starts to drip from these scratches as more and more like up. With enough courage, Red even managed to pull himself closer and bite into his rapist's shoulder and holds on.

Although it doesn't phase Sans' pace, in fact, his pace got even faster, he roars from the bite and his grip tightens feeling the ecto now covering Red's hips shift the nearest bit and start to turn purple. 

With one last thrust his knot sets in with a satisfying pop and holds Sans in place as he cums with a satisfying groan. Leaning down over Red this is probably the closest their faces had ever gotten. Just a few mere inches away. As much as Red would like to take this opportunity to retaliate something different was happening.

"Wh- why am I feeling-?" Whimpering his stomach suddenly starts feeling particularly full like as if Sans' cum hadn't stopped yet for whatever reason? 

Chuckling at his mate's cute surprised face, the bara moves a hand down and gently rubs at the smaller monster's chubby stomach, feeling it shift and slowly stick out more as his cum continues to fill Red up.

"Don't worry your little gremlin heart. It'll stop, just a lot for your ugly little body," Sans teases cruelly and presses into their stomach making red growl and knock his head up against Sans'. "YOU FUCKING-?" Jerking his head back, this unfortunately ruins his mood as he finishes cumming and his knot begins to soften up. 

Cursing, he tears Red's bound hands off him, finally letting the runt properly breath, and then inspects the damage. With his mate mark still solidly on Red's shoulder and their stomach bloated out like they may have eaten enough for two people Sans called it a good enough day.

Nodding slowly, Sans pulls out and slips his pants back up. Cum soon starts dripping out of Red and the monster sighs in relief. "You may be an ugly little shit but you're durable... Definitely gonna keep you." Red did not like the sound of that.


End file.
